New photometric observations of NS VS 01286630 were performed and two sets of fourcolor（B, V, Rc, Ic） light curves（LCs） were obtained. Using the 2013 version of the Wilson-Devinney（W-D） code, we analyzed these d...New photometric observations of NS VS 01286630 were performed and two sets of fourcolor（B, V, Rc, Ic） light curves（LCs） were obtained. Using the 2013 version of the Wilson-Devinney（W-D） code, we analyzed these data. The photometric solutions reveal that NS VS 01286630 is an active detached eclipsing binary（EB） with a high orbital inclination（nearly 90°）. Remarkably, the temperature of the primary component（the hotter star） is higher than the secondary one, but the value of mass ratio q（M2/M1）for NS VS 0128663 is more than 1, which can be explained in that the surface of the secondary component of NSVS 01286630 is covered with big cool starspots. Based on our new CCD mid-eclipse times and the data published until now, variations in the mid-eclipse times were reanalyzed in detail using a weighted least-squares method. It is discovered that the（O-C） diagram of the system shows a cyclic oscillation with a period of 3.61 yr and an amplitude of 0.001 d. The cyclic variation may be caused by the light-travel time effect（LTTE） due to the presence of a third companion, whose mass we calculated as M3 sin（i3） =0.11 M（⊙）. The third body may affect the orbital evolution of the central binary system by transferring angular momentum.展开更多
In this study,we determined the physical parameters of W UMa type contact binaries and their stability of mass transfer with different stellar mass ranges over a broad space by applying the basic dynamical evolution e...In this study,we determined the physical parameters of W UMa type contact binaries and their stability of mass transfer with different stellar mass ranges over a broad space by applying the basic dynamical evolution equations of the W UMa type contact binaries using accretor and donor masses between 0.079 and 2.79 M_(⊙).In these systems,we have studied the three subclasses of W UMa systems of A-,B-and W-type contact binaries using the initial and final mass ranges and we investigated different stellar and orbital parameters for the subclasses of W UMa systems.We examined the stability of the W UMa type contact binaries using the orbital parameters such as critical mass ratio,Roche lobe radius of the donor star and mass ratio of these systems.Thus,we computed the observed and calculated physical parameters of A-,B-and W-type W UMa systems.Moreover,we determined the combined and color temperatures to classify the three subclasses of the systems.Also,we presented the result of the internal stellar structure and evolution of W UMa type contact binaries by using the polytropic model.展开更多
We present the first photometric and orbital period investigations for a neglected totally eclipsing contact binary IP Lyn.The photometric solutions derived from both ground-based and several surveys'observations ...We present the first photometric and orbital period investigations for a neglected totally eclipsing contact binary IP Lyn.The photometric solutions derived from both ground-based and several surveys'observations suggest that it is a shallow contact binary with an extremely low mass ratio of 0.055.The weak asymmetry observed in our multiple band light curves can be interpreted as a result of an active cool spot on the primary.The absolute physical parameters were determined with the Gaia-distance-based method and checked by an empirical relation.Combining the eclipse timings collected from the literature and those derived from our and variable surveys'observations,we find that IP Lyn has been undergoing a secular orbital period increase for the past two decades,implying a mass transfer from the less massive secondary to the primary.By comparing the current parameters with the critical instability ones,we infer that IP Lyn is currently stable in spite of its relatively low mass ratio and orbital angular momentum.Finally,from a catalog of 117 extremely low mass ratio contact binaries,we find that their orbital angular momenta are significantly lower than those of the contact binaries with a relatively high mass ratio,suggesting they should be at the late evolutionary stage of a contact binary.展开更多
We presented photometry for an EB-type totally eclipsing binary,1SWASP J010313.78+352903.7,observed with the Xinglong 85 cm telescope on 2021 October 22.Light curves in five bands(including the TESS data)were analyzed...We presented photometry for an EB-type totally eclipsing binary,1SWASP J010313.78+352903.7,observed with the Xinglong 85 cm telescope on 2021 October 22.Light curves in five bands(including the TESS data)were analyzed by employing the Wilson-Devinney method.The photometric solutions show that it is a contact binary with a relatively low mass ratio(q≌0.28),relatively large fill-out factor(f≌40%)and large temperature difference(ΔT≌1700 K).Max.I-Max.II is up to about 9%of variable light amplitude of the asymmetric light curves.It is well described by double-hot spots model on the surface of the cooler secondary.The two hot spots are both in growing and evolving.They may be caused by two different mechanics,i.e.,magnetic stellar activity and mass transfer.The large temperature difference between the two contact components indicates that they share a non-thermal equilibrium common envelope.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11573063,11611530685)the Key Science Foundation of Yunnan Province(No.2017FA001)+1 种基金support from the staff of the Xinglong 85 cm telescopepartially supported by the Open Project Program of the Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences
文摘New photometric observations of NS VS 01286630 were performed and two sets of fourcolor（B, V, Rc, Ic） light curves（LCs） were obtained. Using the 2013 version of the Wilson-Devinney（W-D） code, we analyzed these data. The photometric solutions reveal that NS VS 01286630 is an active detached eclipsing binary（EB） with a high orbital inclination（nearly 90°）. Remarkably, the temperature of the primary component（the hotter star） is higher than the secondary one, but the value of mass ratio q（M2/M1）for NS VS 0128663 is more than 1, which can be explained in that the surface of the secondary component of NSVS 01286630 is covered with big cool starspots. Based on our new CCD mid-eclipse times and the data published until now, variations in the mid-eclipse times were reanalyzed in detail using a weighted least-squares method. It is discovered that the（O-C） diagram of the system shows a cyclic oscillation with a period of 3.61 yr and an amplitude of 0.001 d. The cyclic variation may be caused by the light-travel time effect（LTTE） due to the presence of a third companion, whose mass we calculated as M3 sin（i3） =0.11 M（⊙）. The third body may affect the orbital evolution of the central binary system by transferring angular momentum.
基金the Space Science and Geospatial Institute (SSGI) -Entoto Observatory and Research Center (EORC)Astronomy and Astrophysics Department for supporting this research。
文摘In this study,we determined the physical parameters of W UMa type contact binaries and their stability of mass transfer with different stellar mass ranges over a broad space by applying the basic dynamical evolution equations of the W UMa type contact binaries using accretor and donor masses between 0.079 and 2.79 M_(⊙).In these systems,we have studied the three subclasses of W UMa systems of A-,B-and W-type contact binaries using the initial and final mass ranges and we investigated different stellar and orbital parameters for the subclasses of W UMa systems.We examined the stability of the W UMa type contact binaries using the orbital parameters such as critical mass ratio,Roche lobe radius of the donor star and mass ratio of these systems.Thus,we computed the observed and calculated physical parameters of A-,B-and W-type W UMa systems.Moreover,we determined the combined and color temperatures to classify the three subclasses of the systems.Also,we presented the result of the internal stellar structure and evolution of W UMa type contact binaries by using the polytropic model.
基金supported by the Joint Research Funds in Astronomy under a cooperative agreement between the National Natural Science Foundation of China(NSFC)and the Chinese Academy of Sciences(Nos.U1931115 and U2031114)Scientific Research Fund of Hunan Provincial Education Department grant No.22A0099+1 种基金the support of the staff of the Xinglong 85 cm telescopepartially supported by the Open Project Program of the Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences。
文摘We present the first photometric and orbital period investigations for a neglected totally eclipsing contact binary IP Lyn.The photometric solutions derived from both ground-based and several surveys'observations suggest that it is a shallow contact binary with an extremely low mass ratio of 0.055.The weak asymmetry observed in our multiple band light curves can be interpreted as a result of an active cool spot on the primary.The absolute physical parameters were determined with the Gaia-distance-based method and checked by an empirical relation.Combining the eclipse timings collected from the literature and those derived from our and variable surveys'observations,we find that IP Lyn has been undergoing a secular orbital period increase for the past two decades,implying a mass transfer from the less massive secondary to the primary.By comparing the current parameters with the critical instability ones,we infer that IP Lyn is currently stable in spite of its relatively low mass ratio and orbital angular momentum.Finally,from a catalog of 117 extremely low mass ratio contact binaries,we find that their orbital angular momenta are significantly lower than those of the contact binaries with a relatively high mass ratio,suggesting they should be at the late evolutionary stage of a contact binary.
基金supported by the Natural Science Foundation of Shandong Province,China(ZR2021QA082)the National Natural Science Foundation of China(No.11922306)the Doctoral Start-up Foundation of Yantai University(SX20B112)。
文摘We presented photometry for an EB-type totally eclipsing binary,1SWASP J010313.78+352903.7,observed with the Xinglong 85 cm telescope on 2021 October 22.Light curves in five bands(including the TESS data)were analyzed by employing the Wilson-Devinney method.The photometric solutions show that it is a contact binary with a relatively low mass ratio(q≌0.28),relatively large fill-out factor(f≌40%)and large temperature difference(ΔT≌1700 K).Max.I-Max.II is up to about 9%of variable light amplitude of the asymmetric light curves.It is well described by double-hot spots model on the surface of the cooler secondary.The two hot spots are both in growing and evolving.They may be caused by two different mechanics,i.e.,magnetic stellar activity and mass transfer.The large temperature difference between the two contact components indicates that they share a non-thermal equilibrium common envelope.
